Firearm



J. D. PEDERSEN March 25 1924.

FIREARM Filed July 14 192C 5 Sheets-Sheet 1 i. Il g/VM??? i@ I', gli?lfieofevzoi: J/z Pedersen) March 25 1924. 1,487,801

J. D. PEDERSEN FIREARM Filed July 14, 1920 5` sheets-sheet 2 f m 1I. A.no ow m n r 7 m W RN m e 8 s llllll Il m N .INIIIIP IIHIwIHHHH I Il I shw mw www mi l n o www .N w 0 2 E l J s DM, M w m m w w P M .w D. d m mJ .nu EN hw. wh, D

March 25 1924 I l I ,l I| l: r l :l `i

Q l m i w" u' March 25 1.924%

J. D. PEDERSEN FIHEARM Filed July 14 1920 5 Sheets-Sheet 5 [live/afar:

J0 2.2961! @rse/2) Patented Wien. 25, i924.

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JGHN ID. IPEDERSEN, 0F JA. "-f WYOMING.

FIR/EAR.

Application led July 14, 1920. Serial No. 396,215.

To all whom it may concern:

Be it known that I, JOHN D. PEDERSEN, a a citizen of the United States,residing in Jackson, in the county of Lincoln and State of Wyoming, haveinvented certain new and useful Improvements in Firearms, of which thefollowing is a specification.

This invention relates to firearms for using two kinds or sizes andpowers of ammunition, having respectively long range and short rangeprojectiles. A principal object of the invention is to furnish a weaponof that class comprising a pair of firearms,preferably eachI having amagazine,-one for each of said purposes, respectively combined in asystem whereby each of said firearms may be used either independently ofor concurrently with the other, and so arranged that while the gunnermay be using one or a first said firearm the other or second one may beheld loaded and the magazine thereof fully charged, in readiness forinstant use without regard to the use or non-use of such firearm.

A further object is to furnish a composite or compound firearm of saidclass in which the two trajectories may be so located that thetrajectory of the short-range projectiles may cross that of thelong-range projectiles in two points, and thereby provide for the propersighting of each said firearms by the use of the same sights, andwithout requiring any changing thereof.

While it has been customary to regard the barrel of a shoulder-arm asbeing carried by the receiver,-this being regarded as the frame,-itshould be noted that the reverse of that view is equally correct, and inmy present improvements, the main barrel is shown arranged to constitutethe carr ing member for the cartridge-supplying an firing means for bothof the barrels. Thus the present system (herein represented in ashoulder-arm form thereof) com rises two complete firearm mechanisms,eac operable independently of the other, these two firearms, however,being organized into one combined pair in which the two have bothstructural and functional coactive relations.

In the present description, the two individual firearms composlng thistwo-mechanism system are sometimes referred to, one of them as thelarger or main firearm, and the other as the small firearm; also, as thelarge barrel firearm and small-barrel firearm. vIt should be understood,however,

that such terms as large and small or other words of similar import orapplication, do not necessarily or impliedly refer to the bore of thebarrels, unless clearly 'so stated, but rather to the size or weight, orboth, since, in practice, while the two barrels may have bores of thesame diameter, the rapid-fire or lower (and usually shorter) barrel doesnot need to be nearly as large externally as the upper or main barrel.

Since the present invention is more especially intended for use inmilita firearms, the form of the primary or largerfiarrel firearmrepresented in the drawings, is designed to substantially correspondwith the socalled Springfield rifle; but, in practice, if required,other kinds or styles of shoulder-arms barrels and mechanisms may beemployed in lieu thereof.

f In the accompanying drawings forming a part of this specification,Fig. 1 is a sideview, drawn on a small scale, for illustrating thegeneral arrangement of a firearm of the shoulder-arm class having theelements thereof organized in accordance with the present invention.

Fig. 2 is an enlarged fragmentary frontend view of Fig. 1, partl insection, showing the aperture in the ayonet shank for passage of theprojectile from the rapid-fire barrel.

Fig. 3, is an enlarged fragmentary vertical section of the rapid-firemechanism in fire position. Fig. 3a is a view similar to Fig. 3, showinga portion of the firing mechanism, the bolt thereof being in extremerear position, and showing a modified form of stop for the bolt.

Fig. 4 is similar to Fig. 3, with the rapid-fire firing mechanism inposition for disassembling.

Fig. 5, is an enlarged fragmental vertical section showing thelong-range and rapidfire firing mechanisms, the rapid-fire firingmechanism being in firing position.

Fig. 6, is a section on the line 6 6 of Fig. 5 in the direction of thearrow, the rapid-fire firing mechanism being shown.

Fig. 7 is a detail sectional view on the line 7-7 of Fi 5.

Fig. 8 is a line 8-8 of Fig. 5.

Fig. 9 is a detail sectional view on the line 9-9 of Fig. 5.

Fig. 10 is a detail sectional view on the line 10-10 of Fig. 5.

etail sectional view on the Fig. 11 is a vertical sectional view, on anenlarged scale, of a portion of the frame of the firearm.

Fig. 12 is a bottom plan View of the portion of the frame shown in Fig.11.

Fig. 13 is a top view, on an enlarged scale, of a bolt and block member.

Fig. 14 is a sectional side view of said bolt and block member.

Fig. 15 is an end view of said bolt and block member.

Fig. 16 is an exterior side view Vof said bolt and block member.

Figs. 17, 18, 19, 20 and 21 are diagrammatic views for illustratingprojectile trajectories. D

Fig. 22 is a fragmentary sectional-view of the main and secondarybarrels illustrating an integral arrangement thereof.

Fig. 23 is an end View of the arrangement shown in Fig. 22.

Fig. 24 is an end View of the main and secondary barrels illustratinganother form of arrangement of these barrels.

Fig. 25 is an end view of the main and secondary barrels illustratingstill another arrangement of these barrels.

In said primary firearm in the form thereof herein shown, (see Figs. 5and 6), the barrel B is relatively` large and rigid and to the rearwardand larger end thereof, has attached thereto a chambered mechanismframe, or receiver,.as F, for containing the usual loading, firing andshellejecting devices or means.

Said receiver is represented as being imbedded in the usual stock, orshoulderpiece, (Fig. 5), which extends forward of the receiver to formthe forestock, S; this is shown fixed in place below the barrel B,

and may be formed in a separate piece from the shoulder piece, in awell-known manner, if desired. This forestock may be held in position byordinary bands b, b. In Fig. 2, the usual bayonet shank, D, is indicatedas being applied to the barrel B in the usual manner, which, being wellknown need not be shown, as d, which shank is provided with an aperturea, through which ma pass the projectiles fired from the smallarrel C,when the bayonet is in pla-ce on the firearm.

A. further feature of the present system relates to the manner in whichthe smallbarrel firearm and the operating mechanism thereof, is housedwithin the fore-stock of the large-barrel firearm. Thus 'the smallbarreland rapid-fire weapon is not only protected from injury (and largelyhidden from observation), but is in constant readiness for instant use,by simply attaching a filled magazine. In practice, the soldier whengoing into action, should first put in place the magazines of each saidfirearm so that either one of these may be first used or the two usedalternately as cecasion may require.

The frame f of said smailer mechanism being located directly below saidmain barrel B, the fore stock S is shown chambered to fit over, oroutside of said frame, and thereby furnishes a guard or coveringtherefor, so the voperator may safely grasp the arm in a positionforward of the main frame F and rearward of the ma azine, as m, whichextends downwardly rom said smaller frame f.Y 'Y Y rFhis frame, f, isshown in a preferred form thereof in Figs. 11, 12. rihe two sidewalls 6,6a, are connected by a rearward part 6", and a forward end portion 6,and

y a cross-Wall 6d, rearward of the maga-- zine socket. Said side-walls6, 6, are further united by the rearward and forward main-barrel clasps,6, 6, respectively; these are fitted to firmly close out the taperingbarrel B, when this lower frame is forced rearwardly over said barrel B,and thus brought against (or near to) the receiver F of thelarge-barrel, or primary firearm in the process of assembling., Vhenthus assembled, a cross-pin, as p, (Fig. 5) may be used for releasablyholding the frame f upon its said carrier member, or barrel, B. 1n Figs.11, 12, guides 6g, 6h, on one side, and 6, 6", on the other side, areshown arranged for engaging and guiding the power-block, at 10, Fig. 5,of said mechanisrn of the small-barrel rearm.

The form of combined power-block and breech-bolt E shown in thedrawings, Fi 13 and 16 inclusive, comprises a slidab ysupported mainportion 5, the forward ezttension,- or breech-bolt 5, and a lower andrearward extension, 5b, provided with a handle or finger-piece 5. Thisrearwardly extending part, 5b, serves as a chambercloser, or guard platewhen the block iS in forward position, as will be seen by comparingFigs. 3 and 5. ln this firing-position of the power-block, Fig. 5, theboltportion 5a extends over the magazine m, and comes close to, butpreferably not quite into Contact with, the rear end face, 3, of thebarrel C; this forward movement of said block E is herein shown as beinglimited by a transverse face 5d, of the block coming into contact with acorresponding face 7g of the transverse wall 6d, of the frame Therearward movement or workingstroke of block E may be limited by a stop,as G, engageable in recesses 81, 8k in the frame 7, Figs. 3v and 5arranged to be withdrawn w en desired, to thereby permit said block toretracted to the more rearward position thereof in Fig. 4, for therebydislil@ engaging the bearing faces 5e, 5f, Fig. 16,

and the corresponding faces, not shown, of

meneer lowered directly downwardly out o frame f, when disassembled, andmay be re` placed by following a reverse operation. To provide for theseoperations, said guides 6, 6, 61, 6k, are shown of suitable length andare suitably positioned to engage by a suiicient distance, as 11, (Fig.3)), when, in the assembled mechanism, said lock E is retracted onl tothe end of its said normal working stro e.

Said block retraction-limiting stop, G, may be operably supported byattachment to one end of a flat spring as 12, (Figs. 3 and d), the otherend 12', of which is removably aiixed, as by a screw 13 to the block Eor to some part appurtenant thereto. 1n Figs. 3, 4 and 5, thisattachment is made by extending said stop carrying member, 12, forwardlyfrom the stop and there fixing said member by a screw 13, to theaforesaid rear ward extension 5 of the power-block. However, other formsof such a stop may be employed if desired, and in Fig. 3a is shown onesuch other form, it consisting of a plug, G', having a threaded portion57, and slotted head 58, whereby this stop may be placed and removedafter the manner of anv ordinary machine-screw.

lln,J the present instance, l have illustrated my present improvementsby an arrangement of mechanism operating onv the socalled blow-backprinciple, this being, in practice, one of the more simple kinds. rlhissystem, however, requires a slide or reaction member having aconsiderable weight relative to the power of the cartridge to be used,and hence is not so well adapted for usin high ower cartridges whn thetotal welght of t e firearm is limite The cartridge as H, having beenproperl placed in barrel C (Fig. 5), on belng fired reacts against slideE, which thus constitutes a reaction member or power-slide. The weightof slide E should be such that the cartridge,-this being speciallydesigned and loaded therefor,w1ll impart to said slide a rearwardmovement of suiiicient stroke and power to perform, directly orindirectly, the subsequent operations of shellextraction and ejection,and of reloading the firearm.

Cn being driven back from the firing position thereof, Fig. d, the slidecompresses the operating spring 14, and retracts the bolt-face 5grearward of the upper most cartridge in the magazine m, so that on aforward actuation of the slide to firing position, said bolt face drivessaid cartridge out. of the magazine and into the barrel-chamber, as at15, Fig. 5. lf, during said loadin operation, the scar-hook 16, standsforwar or up (as in Fig. 6), the sear-hook will engage with the face 17of the firing pin P, and thus hold said pin retracted until aftertheloading-in operation is completed, so the several said parts' will bepositioned as indicated in Fig. 5, ready for firing the cartridge; thisis now accomplished, in the specific form of devices shown, by pullingback trigger il', which by means of the intermediate pushrod R, acts toretract the scar to the firing-pin-releasing position shown in dottedlines, Fig. 6. Said pin PI being thus releasedis driven forward by itsactuating spring 18, and the point thereof strikes the cartridge H,thereby firing the cartridge in the usual manner. v

The operator may now proceed in either one of two Ways. First, on havingreleased the firing-pin as described, he may instantly release thetrigger and thereby restore the Sear-lock to its ring-pin engagingposition, so that the bolt-mechanism (this eing cartridge-actuated asbefore) Will reload the barrel and then remain idle, but in firingposition. Or the operator may hold the scar retracted, and out of itssaid tiring-pin-engaging position, until after the completion of saidloading operation. In this case, the firing pin normally is drivenforward by its spring 18, and upon the sudden stoppage of the slide E(by the cartridge being fully seated in the barrel) acts by its momentumto fire the cartridge and thus inaugurate a second loading operation.Thus, by holding the sear retracted, the loading and tiring operationsbecome automatic and may so continue until the supply of cartridges inthe magazine is exhausted.

In this automatic mode of action, the slide E is driven forward by itsspring 14 at the same time the firing-pin P is driven forward by thespring 18, and thus said members E and P, are advanced by the concurrentaction of the two springs 14, 18, thereby obtaining a maximumacceleration of the loading operation, or loading-in movement of thesliding bolt E, which also increases to a maXimum,-in View of itsweight,-the momentum of said pin P, for effecting the firing of thecartridge in the manner eX- plained. To insure an effective action ofthe firing-pin, by its momentum when going forward with the slide, thispin may be made of such weight as may be found necessary or desirable inany particular instance.

In some instances, the two barrels B, and.

projectiles used in main barrel B will have (the same as those now emloyed) a low, or dat, normal trajectory, eing of highpower and longrange. The projectiles for the small barrel will be ordinarily, of lessweight and power and consequently o shorter range, suitable in tact, forthe closerange work for which the small barrel firearm is especially7intended. This relation of the two norma trajectories is indicated inthe dia ram Fig. 17, Where the slightly curved ine 23 represents thelong-range normal trajectory, and the similar but more curved line 24represents the short-range normal trajectory from the small-barrel C,the sight-lines being approximately represented by dash-line 25. Tt willbe noted that said trajectories cross at points 26 and 27 and betweenthese points have only a slight deviation, the one from the other, sothat within a considerable distance. the sights as adjusted for thelarge barrel B are also suiliciently correct for the small barrel C.Thus the soldier when surprised by a nearby enemy (and having bothmagazines in place) can instantly bring into actlon the rapid-fireautomatic mechanism Without having to change the sights or make anyallowance for the di'erent range.

In preparing :for the manufacture of the rearm, and in the arranging ofthe amount of said barrel-axes convergence this may usually be made lessin angular measurement than the taper of the main barrel B, so that whenthe small-barrel C is truly cylindrical, the space between the twobarrels may be greater at the forward end of said small barrel than itis near the rearward end thereof. This arrangement permits theheat-transmitting, or filling piece J', (hereinafter more fullydescribed) to have a corresponding taper, depth-wise thereof, so that itmay be slid onto said small barrel with the frame f from the front endthereof, when the forward astenings at bb and the front end stock S arefirst removed; and thus brought into a close-fitting relation to saidupper barrel B.

In Fig. 20, at a position indicated by line 28, this being intermediateto the two trajectory intersections 26 and 27, the two trajectory curves23, 24, are tangent, respectively, to two straight lines 29 and 30,which are parallel. Thus it may be said that at a position remotelydistant from the barrels,- preferably in a mid-range zone,-the normaltrajectory-curve having the small curvature, and the normaltrajectory-curve havin the relatively greater curvature, have at sucposition, parallel tangentlines. For securing this result, the secondbarrel C is to be properly positioned relative to said main barrel B,for bringing said trajectory curves into the described relationship,this readily may be done by the use of suitable barrel-holding meanswhereby said second barrel will be lredly ositioned in the tirearm andrelative to t e main barrel in a non-parallel manner, so that the axesof these barrels will have a suihcient amount of the forward axialconver ence.

Should the cartridges use in said second barrel C, be of an abnormallylow power, the trajectory-curve 24 of Fie'. 21 would, of course, belowered according such a result is indicated b line 2l, where saidtrajeetories 23, 24, o not actually intersect each other.

Tn this instance, however, the curve 24, at some position, as 31, whichis remotely distant from the muzzle-ends of the barrels, 1s tangent to aline, 30, which is parallel to another line, 29, that is tangent at 32to said other trajectory 23. Thus the tangency relation to parallellines as above described, applies equally to the trajectory positionsillustrated in Figs. 20 and 21 respectively.

The said mid-range zone is deemed to be located in space at a positionabout mid-way of that arc (as 33, Fig. 20) of the shortrange normaltrajectory, 24, which lies above the battle-range sight-line, as 25, forthe normal trajectory-curve 23, of the longrange barrel, B. In Fig. 20,said mid-range zone may be regarded as extending from point 26 to point27 but, while the measurement of this distance may be varied inpractice, the point of tangency as 34, Fig. 20, should ordinarily be asremotely distant from the rea barrels, as the point, 26, at which theshort-range normal trajectory 2e first intersects the long-range normaltrajectory 23.

'ice

Tn the diagram Fig. 18, line 25 represents the so-called battle-rangesight-line, which meets the long-range normal trajectory at a dlstantpoint, as 35; in practice this distance may be assumed as being 50()yards, an approximate midway point, as 36, of said battlc-range may beabout 200 yards remotelydistant from either end of said range. Also, inFig. 18, the short-range normal trajectory, 24, is shown so located, dueto the positioning of lower barrel B, as to bring the lntersectionpoints 26, 27 approximately midway from the barrel C to the point 35.The arc 33 of said short-range trajectory extends from the firstintersection point 26 to the second intersection point 27, and, forconvenience, is herein designated as the intersection are. Thus said arc33 may be said normally to extend substantially* equal distancesforwardly and rearwardly of the approximatin battle-range lengt orportion, of said mainbarrel trajectory.

When the main and secondary barrels are discharged concurrently, themark at the points 26 and 27, due to this intersection of trajectoriesat these points, will be submidway point 36 of the jected to theconcentrated fire of the main I and secondary barrels, and the zonebetween the points 26 and 27 becomes a danger zone relative to thisconcentrated fire, a feature particularly valuable in use of the firearmas a military weapon.

The precise location of said sight line 25 may be determined, inpractice, by the usual rearward and forward sights, as 54, 55,respectively, which are herein shown only in a symbolic form, suflicientfor the diagrammatic representations in said views Figs. 17 to 20,inclusive.

The nature and importance of said doubleintersectionof the trajectory in23 and 24, and of the curvature in the same direction of the twotrajectory-arc, 33, between said points of intersection, will be mademore clear, by a comparison of Fig. 18, with the lines shown in Fig. 19,in which the longrange barrel B, has the axis thereof in line 34. If,now, a short-range firearm should be placed above main barrel B, as forinstance, Fig. 19, the trajectory 24, can intersect said ong-rangetrajectory 23, in only one point, as 38. And, when a short-rangeprojectile is fired from the main-barrel B, (of the long-range firearm),its trajectory 23', diverges downwardly from the longrange trajectory23, so that at a short distance away, as at 39,.the amount, 40 of suglidivergence will be too great for satisfactory results, unless adifferent sighting shall be specifically provided there-for, and thismethod is not a'dependable one, in practice, since it adds anotherfeature requiring forethought and attention by the soldier at a timewhen he cannot be trusted to meet any such extra requirement. But, bymeans of the present improvement, as clearly indicated in Figs. 18 and20, the soldier is relieved of all such responsibilities, since the onepair of sights are properly usable at all times for both firearms of thesystem.

The herein described combining of said pair of firearms in a systemhaving the short-range arm below the barrel of the long-range arm, andthe axial convergence thereof as set forth, accomplishes the novel andimportantv result explained as regards the sighting, and one which isnot obtainable in com osite firearms having the smallbarrel a ove thelarge-barrel firearm, nor in such arms as the Morris tube or others inwhich the two kinds of projectiles, longrange and short-range, are usedalternately in the same bore. In these cases, the two trajectories cancross or coincide but once, and in the latter said cases the twotrajectories are tangential at the muzzle of the barrel, and thenceconstantly diverge, without crossing at any point of distance.

In thus describing said forward converence of the barrel axes it hasbeen assumed or convenience, that the so-called line of departure of theprojectile coincides with the barrel axis. It is known however that saidline of departure may not exactly coincide with the structural axis ofthe barrel, and hence it is to be understood that when, in the processof sighting (as this is now practiced by adepts 1n this special art) itis instance, differ materially from the saidl structural axis.

The intersecting of trajectories which isV herein described in respectof Fig. 18, and which is specified in certain of the claims, should beunderstood as referring to vthe crossing of the long-range trajectory23, by the short-range trajectorya, 24, when these are considered asthey would appear when viewed from one side of a vertical plane, thisbeing the manner of illustration in said Fig. 18. It should beunderstood, however, that in ractice, the actual path or line-offiight othe short-range projectile may not, in a strict or mathematical sense,intersect the actual path of vthe long-range projectile, since usual ythere will be a slight lateral movement or sway of one or the otherprojectile to the right-hand or left-hand, due to windage, or to otherwell-known but variable causes. But these variations in the'lines offlight are ordinarily of a negligible amount, especially if the firearmbarrels have been duly positioned therefor; and, in any such case, thelateral variation does not impair or materially affect' the saidintersections as represented in said Fig. 18, nor the practicaloperation of the firearm as regards precision of lire.

From the foregoing description as illustrated it will be seen that themain barrel, as B, 1s fitted b its rifiing and construction and isequippe with cartridge-placing and firing means for the firing-on theso-called fiat7 trajectory-, of long-range and relatively heavyprojectiles, and therefore may be said to have the small-curvaturetrajectory which such projectiles normally have when fired byhigh-powered cartridges used in rifle-barrels of the kind referred to.Similarly the second barrel, as C, is fitted and equipped for firingprojectiles of a rela` tively less weight, and much shorter range, beingfired by relatively low-powered charges. Hence, this second barrel maybe said to have a relatively greater curvature of trajectory, ascompared with the described trajector of said main barrel. And, in thecomplete rearm, the two said barrels,

. rang? T is barrel, on account of the normally rapid operation of theautomatic loading and iirin mechanism, naturally acquires heat ra i 1and hence, (followin a general princip e a eady well-known), prefer toprovide this barrel C, with heat transmittin and radiation means foraccomplishing sai purposes.

For directly receiving heat from the barrel C, said barrel is shownencased in a highly conductive sleeve, as J, which may extend nearly thewhole length of the barrel, and be made of an aluminum alloy, ifdesired. This sleeve J has a large radiating surface, and carries anupward extension 41, Fig` 8, which may be broadened out at its upperedges, as 42, 43, and be shaped to t closely to the under surface, as at44, for thereby transmitting a larger proportion of the heat, to saidmain barrel B, which thus becomes an heat-absorbing reservoir. This heatthus transferred up into barrel B, this havin a large mass and surface,will be rapidly istributed along the length. thereof and so radiatedinto the atmosphere from the large amount of the exposed barrel surface.

In ractice, I prefer to rigidly but releasabl one end,-preferably therearward en ,-'-of sleeve J to small barrel C and this may be done by across-pin as p1 (Fig. 5), or by other suitable means. This arrangementserves to hold the rearward end-face 45, of the sleeve in fixed.relation to the rearward end 46 of the barrel C, so that the slidingmovement, due to variations in temperature, of the sleeve on barrel Cwill extend to and mostly occur near the forward end of the sleeve; toprovide for this action, the sleeve should be itted closely upon thebarrel, but be readily slidable thereon under the `powerful force due tothe heat-variations.

A further cooling of the main barrel B may be effected by means of apeculiar feature of the described two-barrel arrangement. The forwardend 47, Fig. 2 of the small barrel C, is shown located a short distancebelow and somewhat rearward of the muzzle, 48, of said main barrel. The'gases emerging from small barrel C spread into a cone-like form and thusoperate to blow forwardly the air at and. surrounding the forward end,48, of said main 1 l. This in.

i 18) t e normally longturn, tends in an evident manner to draw airthrough and thereby cool the bore of the main barrel, provided therearward end thereof is open to the influx of air; for this purpose, theo rater lnay have the main arrel unload small barrel for anyconsiderable number ofshots. An important advantage of this two-barrelcomposite fire-arm, arises from the circumstance that the long-range andshortrange projectiles may each be given a speed of rotation suited tothe weight and velocity of advance thereof. Thus each of the barrels B,C, can now be specially riied each for its own special requirements, andhave a degree of twist in its rifling as properly requlred by thecartridge and projectile to be used in the barrel. As a general ruletherifling of the long-range barrel should have a relatively rapid twist ascompared with that of the short-range barrel. And, to fire short-rangeprojectilesl through a barrel rifled for high-velocity long-rangeprojectiles tends to produce serious alterations of movement during theflight of the shortrange projectiles and thus impair or destroyprecision of fire. By avoiding'the said objections, the short-rangeammunition is readily made to covery a greater effective ra e than whenused in the long-range barrel of a high-power rifle, and this importantgain is secured in my present improvements, in connection with thepeculiar intersection of trajectories, as already eX lained.

In some instances, the two arrels B and C may be joined integrallyeither before or after the bores 49, 50, respectively are formedtherein. One construction of this kind is shown in Figs. 22 and 23,where the second barrel C, is. shown below the main barrel B and formedin one piece therewith. This form, however, while amply providing for arapid transmission of heat from said lower rapid-fire barrel C to theupper and larger barrel B, has the disadvantage of being diliicult tomanufacture in an economical manner. A. further objection is that whensaid lower barrel is highly heated (as necessarily occurs withrapid-fire for any considerable period), the longitudinal extensionresulting therefrom operates to bend or iex the upper barrel B, and thustends to disturb the sighting relation thereof; this is practicallyavoided in the more elaborate construction herein illustrated in theprincipal'views, Figs. 3, 4, 5, 7 and 8.

The aforesaid objections are normally reduced in the modified form shownin Fig. 24, where the lower and smaller barrel C is shown integrallyprovided with a sleeve 51, extending over and slidably connecting withthe upper and larger barrel B, so that by a sliding action of saidsleeve 51 upon barrel C, each Vof the barrels may elongate and conwhendesiring to usel the,

tract longitudinally and inde endently of the other, Without subjectingt e other to a material amount of the said barrel-flexin stress. Thisconstruction may be modifi in a rever'sely-arranged manner by the planshown in section only, in Fig. 25, where the main barrel B is providedwith a sleeve 52, within which the lower barrel C is encased in a mannerto ermit the described elongation and contraction thereof Whilepreservlng or providing for a large heat-transmitting contact orrelation between the two barrels.

The special :forms of barrel-construction illustrated in said Fi s. 24and 25 are not specifically claimed erein. In each of these forms, itwill be seen, the two barrels B, C, have between them aheat-transmitting means, which is also a means of directly and fixedlypositioning the smaller and rapid-fre barrel C underneath the mainbarrel B, these two barrels being arranged with the required forwardaxial convergence. In practice, when a sleeve, as 51, Fig. 24, or 52,Fig. 25, ma be employed, this sleeve should, preferab y be maderelatively thin, so that it may readily expand diametrically in anelastic manner under the variable heating action and stress to which itmay be subjected.

The intermediate heat-transmitter, as J, Fig. 8, when not inte ral witheither barrel, has the advantage o being expansible and contractiblelongitudinally' to a different degrec from either barrel and .of doingthis without subjecting either barrel to any flexing stress due to suchdifference. This fea ture provides for lmaking said member J of a metalhaving a higher heat-transmitting power than the metal of which thebarrels are made, these being in present practice, necessarily made ofsteel when for use in high-power and in ra id-fire firearms. Thus, saidmember J may oe made of copper or of a composition consistin in part ofcopper or like metal having a lugh heat-conductivity and thereby providea highly effective heat-absorbing element actin in some respects as aheat-reservoir, and in combination with each of the said barrels.

For convenience in the describing and defining herein of devices andelements, certain terms of direction have been used (in a conventionalmanner) for indicating positions and relations of various members anddetails ofthe mechanism; and it is to be understood that such terms, (asfor instance, up, down, above, below, forward, rearward, and the like),are intended to refer to the stated positions or relations at a timewhen the firearm shall be held in a normal position for use,-that is,held with the main barrel about horizontal and with the centerplane ofthe forestock directly underneath the axis of said barrel,in F ig. 8,said center-plane is indicated by line 53.

In the particular form of main-barrel firearm mechanism illustrated inFigs. 1, 5, 6, the barrel B is shown of the breech-loader type, and asbeing equipped with a handoperated cartridge-placing or loadingmechanism, this consisting of the Ordinar breechbolt N, which is orshould be supp emented by the details usually a purtenant thereto (notherein fully shown including means for firing the loaded-in cartridge.It should be understood, however, that in some instances, or whenpreferred,and within the purview of the present invention,-this firearm,instead of having-said main barrel fitted with such a hand-operatedequipment for the loading-in and firing o erations, may have anauto-loading and firlng mechanism, and that, for such purposes anysuitable kind of the latter mechanisms,- of which several specificconstructions adaptable therefor are already well-known,- may be soemployed.

The improved cartridge-placing and firing mechanism which is hereinshown and described, for the lower or secondary barrel C, is'deemedftobe especially suitable for use in connection with such a second barrelin a compound or two-mechanism firearm of the shoulder-arm Aclass hereinset forth. This mechanism, however, may be applied to single-mechanismfirearms. Also, it should be noted that in some instances, or whendesired, a different breech-action or form of mechanism may be adaptedto said secondary firearm for placing and firing the cartridges for usetherein.

Having thus described my invention, I claim:

1. In a firearm, 4in combination, a main barrel for firing long-rangeand relatively heavy projectiles having a normal trajectory of smallcurvature, and a second barrel for firing short-range projectiles havinga normal trajectory of relatively greater curvature than the firstprojectiles; the second barrel being o eratively arranged and supportedin the rearm adjacently to and beneath the main barrel, the bore of thesecond barrel being in permanent converging orward and upward relationto the bore of the main barrel, whereby the trajectory of theprojectiles from the second barrel intersects upwardly the trajectory ofthe projectiles from the main barrel at a point remote from the muzzlesof said barrels.

2. In a firearm, in combination, a main barrel for firing long-range andrelatively heavy projectiles havmg a normal trajectory of smallcurvature, and a second barrel for firing short-range projectiles havinga normal trajectory of relatively greater curvature than the firstprojectiles; the second barrel being operatively arranged and suportedin the firearm adjacently to and neath the main barrel, the bore of thesecond barrel beingiin ermanent converging forward and u war relation tothe bore of the main barre whereby the trajectory of the projectilesfrom' the second barrel intersects u wardly the trajectory of theprojectiles rom the first barrel at a point remote from the muzzle ofsaid barrels, and Aintersects said trajectory downwardly at a secondoint more remote from the muzzles of said4 arrels than said first point.

3. In a firearm, in combination, a Amain barrel for firing long-rangeand relatively j heavy projectiles having a normal trajectory of smallcurvature, and a second barrel for firing short-range projectiles havinga normal trajectory of relatively greater-t curvature than the firstprojectiles, firing mechanism and trigger mechanism for the main barreland firing mechanism and triger mechanism for the second barrel; thearrels being dischargeable separately or concurrently; the second barrelbeing operatively arranged and supported in the firearm adjacently toand beneath the main barrel, and the bore of the second barrel being inpermanent converging forward and upward relation to the boreof the mainbarrel.

4. In a firearm, in combination, a main barrel for firing long-range andrelatively heavy rojectiles having a normal trajectory of smallcurvature, and a second barreLfor firing short-range projectiles havinga normal trajectory of relatively greater curvature than thevfirstprojectiles, firing mechanism and trigger mechanism for the-main` barreland firing mechanism and trigger mechanism for the second barrel, thebarrels being dischargeable separately or concurrently, and the secondbarrel being operativel arranged and supported in the firearm ad)jacently to and beneath the main barrel, and the bore of the secondbarrel being in permanent converging forward and upward relation to thebore of the main barrel.

5. In a firearm, in combination, a main barrel, a second barrel arrangedin the firearm adjacently to the main barrel, firing mechanism andtrigger mechanism for the main barrel, and firing mechanism and triggermechanism for the second barrel, the barrels being diischargeableseparately or concurrently, and the second barrel being dischargeableautomatically at will for rapid fire thereof.

6. In a firearm, in combination, a main barrel, a second barrel arrangedin the firearm adjacently to the main barrel beneath the main barrel,firing mechanismand trigger mechanism for the main barrel, and firingmechanism and trigger mechanism for the second barrel, the barrels beingdischargeable separately or concurrently, and the second barrel beingdjschargeable automatically at will for rapid fire thereof.

7. In a firearm, in combination, a main barrel-for firing long-range andrelatively heavy projectiles having a normal trajectory of smallcurvature, a. second barrel for firing short-range projectiles having anormal trajecto of relatively greater curvature than t e firstprojectiles, firing mechanism and tri ger mechanism for the main barrel,and firm mechanism and triger mechanism for e second barrel, the arrelsbein dischargeable separately or concurrently; t e second barrel beingoperatively arranged and supported in the firearm \adjacently to andbeneath the main barrel,

the bore of the second barrel converging forwardly and upwardlyrelatively to the main barrel, whereby the trajectory of the projectilesfrom the lsecond barrel intersects upwardly the trajectory of theprojectiles from thel main barrel at a point remote from the muzzles ofsaid barrels, and intersects said 4trajectory downwardly at a secondoint more remote from the muzzles of said Barrels than said first point,and when the barrels are discharged concurrently providing concentratedfire from said barrels at said points of intersection.

8. ln a firearm, in combination, a main barrel for firing long-range andrelatively heavy rojectiles having a normal trajectory of smallcurvature, a second barrel for firing short-range projectiles having anormal trajectory of relatively greater curvature than the firstprojectiles, firing mechanism and trigger mechanism for the main barrel,and firing mechanism and trigbger mechanism for the secondv barrel, thearrels being dischargeable separately or concurrently, the second barrelbeing ischargeable automatically at willv for rapid fire thereof; thesecond barrel being operativel arranged and supported in the firearm ajacently to and beneath the main barrel the bore of the second barrelconverging forwardly and upwardly relatively to the bore of the mainbarrel, whereby the trajectory of the projectiles from the secondbarrel-intersects upwardly the trajectory of the projectiles from themain barrel at a point remote from the muzzles of said barrels, andintersects said trajectory( downwardly at a second point more remotefrom the muzzles of said barrels than said first oint, and when thebarrels are -discharge concurrently, and the second barrelautomatically, providing concentrated fire from said barrels at saidpoints of intersection.

9. In a firearm, in combination, a main barrel, a second barrel oratively arranged and supported in the rearm adjacent to and beneath themain barrel, and conductive means having an extended rtion broadened atits edges interpose between said barrels extending longitudinally of thebarrels for substantially the full length of the second barrel andcontacting with both barrels for utilizing the main barrel for disposingof heat generated in the second barrel.

10. In a i'earm, in combination, a main barrel, a second bai-reloperatively arranged and support-ed in the lfirearm adjacent to and"beneath the main barrel, and a sleeve on the second barrel having anextended portion broadened at its edges, the sleeve being interposedbetween said barrels and extending longitudinally of' the barrels forsubstantially the full length of the second barrel and contacting withboth barrels for utilizing the main barrel for disposing of heatgenerated in the second barrel.

11. In a firearm, in combination, a main barrel, a second barreloperatively arranged and supported in the firearm adjacently to the mainbarrel, and means interposed between said barrels for utilizing the mainbarrel for disposing of heat generated in the second barrel; said meansconsisting of a member comprising a hollow lower longitudinal portionand a longitudinal upper surface curved in cross-section, said lowerportion providing a sleeve for the second barrel, and said upper surfacecontacting with the under surface of the .main barrel and extendinglongitudinally of said barrel.

12. In a firearm, in combination, a main barrel, a second barreloperatively arranged and supported in the firearm adjacently to andbeneath the main barrel, and means interposed between said barrels forutilizing the main barrel for disposing of heat generated in the secondbarrel; said means consisting of a member comprising a hollow lowerlongitudinal portion and a longitudinal upper surface curved incross-section, said lower portion providing a sleeve for the secondbarrel, and said upper surface contacting with the under surface of themain barrel and extending longitudinally of said barrel. v

13. A shoulder-arm comprising, in combination, a stock having abutt-stock portion and a chambered forestock portion; a pair of barrelsspaced apart and comprising a relatively long and heavy main barrelfixedly mounted on the stock and equipped for firing long-rangeprojectiles, and a relatively shorter and lighter rapid fire barrelequipped with mechanism for firing shortrange projectiles, andsupportively and rigidly connected to and located underneath said longbarrel and housed within said chambered portion of the forestock, and aheat-transmitting member interposed longitudinally between andcontacting with each of said barrels whereby to utilize said main barrelfor disposin of heat generated in the ra id-fire barrel.

14. n a firearm, in combination, a main barrel, a second barreloperatively arranged and supported in the firearm adjacently to' andbeneath the main barrel, `firing' mechanism for the main barrel, andfiring mechanism for the second barrel; the firing mechanism forthefsecond barrel comprisin a reciprocable power block and breech Eoltretract-able by explosion gases and proj ectable by spring means.

15. In a firearm, in combination, a main barrel, a second barreloperatively arranged and supported in the firearm adjacently to andbeneath the main barrel, firing mechanism for the main barrel, andfiring mechanism for the second barrel; the firing mechanism for thesecond barrel comprisin a reclprocatable power-block and breech-boltprovided with an operatively arranged firing-pin, the power-block andbreech-bolt being retractable by explosion gases and proj ectable byspring means.

- 16. In a firearm, 1n combination, a main barrel, a second barreloperatively arranged and supported in the firearm adjacently to andbeneath the main barrel, firing mechanism for the main barrel, andfiring mechanism for the second barrel; the firing mechanism for thesecond barrel comprising a reciprocatable power-block and breech-boltprovidedwith a spring actuated firing-pin, the power-block andbreech-bolt being retractable by explosion gases and projectable byspring means.

17. In afirearm, in combination, a main barrel, a second barreloperatively arranged and supported in the firearm adjacently to andbeneath the main barrel, firing mechanism and trigger mechanism for themain barrel, and firing mechanism and trigger mechanism for the secondbarrel; the firing mechanism for the second barrel comprising areciprocatable power-block and breechbolt retractable by explosion'gases and projectable by spring means; the trigger mechanism for thesecond barrel comprising means for releasably retaining the power-blockand breech-bolt in retracted position and trigger operated meansco-operating with said releasable retaining means for operating thesame.

18. In a firearm, in combination, a main barrel, a second barreloperatively arranged and supported in the firearm adjacently to andbeneath the main barrel, firing mechanism and tri ger mechanism for themain barrel, and ring mechanism and trig er mechanism for the secondbarrel; the firlng mechanism for the second barrel com rising areciprocatable power-block and breechbolt retractable by explosion gasesand proj ectable by spring means; the trigger mechanism for the secondbarrel comprising a catch-lever for releasably retaining the power-blockand breech-bolt in retracted position and a trigger operated push-rod,for operatin said catch-lever.

19.l In a rearm, in combination, a main barrel, a second barreloperativelyarranged and supported in the firearm adjacently to andbeneath the main barrel, firing mechanism and tri ger mechanism for themain barrel, and ring mechanism and trigger mechanism for the secondbarrel; the firing mechanism for the second barrel comprising areciprocatable power-block, and reechbolt provided with an operative]arranged firing-pin, the power-block and reech-bolt bein retractable byexplosion gases and project-a le by spring means; the trigger mecha-Vnism for the second barrell comprising a catch-lever for releasablyretaining the power-block and breech-bolt in retracted position and atrigger operated push-rod for operating said catch-lever.

20. In a firearm, in combination, a main barrel, a second barrel shorterthan the first barrel o eratively arranged and supported in the rearmadjacently to and beneath the main barrel, and a bayonet shank carriedby the main barrel provided with an aperture for passage therethrough ofprojectiles discharged from the second barrel.

21. In a firearm, in combination, a main barrel, a second barrel shorterthan the first barrel operatively arranged and supported in the firearmadjacently to and beneath the main barrel, the bore of the second barrelconverging forwardly and upwardly relatively to the bore of the mainbarrel, and a bayonet shank carried by the main barrel provided with anaperture for passage therethrough of projectlles discharged from thesecond barrel.

22. A firearm comprising, in combination, a stock fitted and furnishedfor carrying thereon an upper barrel and its connected cartridge-placingand firin mechanism said stock havmg a chambere fore-stock portion; an uper main barrel provided with cartridge-p acing and firing mechanism andrigidly but releasably mounted on said stock, and having the muzzlethereof extending to a position forward of said forenism, and the muzzleof said second barrelV being in position for the gases dischargedtherefrom `to drive forward gases at the muzzle of the main barrel forthereby producing an air current through the bore of said main barrel,the bore of the main barrel being open atbreech and muzzle at the timeof dlscharge of the second barrel.

23. A firearm comprising, in combination,

a stock fitted and furnished for carryin thereon an upper barrel and itsconnect cartridge-placing and firin mechanism, said stock having achambere fore-stock portion; an u per main barrel provided withcartridge-p acing and ring mechanism and mounted on said stock, andhaving the muzzle thereof` extending to a position forward of saidfore-stock; a second and shorter barrel' and connected loading andfiring mechanism therefor, housed Within said chambered fore-stock, thebore of the main barrel being open at breech and muzzle at the time ofdischarge of the second barrel, and located below said main barrel andforward of the said loading and firing mechanism of themain barrel; and,means for transmitting heat from said second barrel to the main barrel,the muzzle of said second barrel being in position for the gasesdischarged therefrom to displace by driving forward the gases at themuzzle of the main barrel for thereby producing an air current throughthe bore of said main barrel, and thus convey away heat transmitted fromthe second barrel.

1 JOHN D. PEDERSEN.

l/Vitnessesz HARRY WAGNER, C. J. Panerai-m.

